CVE-2021-36222

ec_verify in kdc/kdc_preauth_ec.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.18.4 and 1.19.x before 1.19.2 allows remote attackers to cause a NULL pointer dereference and daemon crash. This occurs because a return value is not properly managed in a certain situation.

Published: 2021-07-22 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-36222 is rated Moderate Risk (59.3/100): CVSS High severity, with high exploitation likelihood (EPSS 6.62%, 91th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-36222

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-12 9.23% 6.62% -2.61%
2 2026-03-28 8.01% 9.23% +1.21%
3 2026-01-08 — 8.01% —

Full EPSS history (32 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-36222

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-36222

OS Trackers for CVE-2021-36222

vendor priority summary link
alpine high CVE-2021-36222: 1 source package rows (krb5); 8 state rows across 8 repos (3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 8, open 0. https://security.alpinelinux.org/vuln/CVE-2021-36222
debian not yet assigned CVE-2021-36222 not yet assigned priority: Debian including 1 source packages (krb5), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-36222
gentoo normal CVE-2021-36222: 1 GLSA(s) (202405-11), 1 atom(s) (app-crypt/mit-krb5); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-36222
redhat medium — https://access.redhat.com/security/cve/CVE-2021-36222
suse high CVE-2021-36222 severity important: SUSE including 674 source package names (0.1.0:krb5-1.16.3-3.21.1, 0.1.75:krb5-1.16.3-3.21.1, …), 1523 product×package rows across 219 product lines (Container bci/bci-init, Container bci/dotnet-aspnet, … (219 product lines)): Fixed 1227, Known Not Affected 154, Known Affected 142. https://www.suse.com/security/cve/CVE-2021-36222/
ubuntu medium CVE-2021-36222 medium priority: Ubuntu including 1 source packages (krb5), 13 status rows across 13 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, trusty, upstream, xenial): not-affected 9, released 3, ignored 1. https://ubuntu.com/security/CVE-2021-36222

Affected software / configurations for CVE-2021-36222

Vendor Product Version Raw CPE
mit kerberos_5 < 1.18.4 cpe:2.3:a:mit:kerberos_5:*:*:*:*:*:*:*:*
mit kerberos_5 >= 1.19.0, < 1.19.2 cpe:2.3:a:mit:kerberos_5:*:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
netapp active_iq_unified_manager — cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:*
netapp active_iq_unified_manager — cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:windows:*:*
netapp oncommand_insight — cpe:2.3:a:netapp:oncommand_insight:-:*:*:*:*:*:*:*
netapp oncommand_workflow_automation — cpe:2.3:a:netapp:oncommand_workflow_automation:-:*:*:*:*:*:*:*
netapp snapcenter — cpe:2.3:a:netapp:snapcenter:-:*:*:*:*:*:*:*
oracle mysql_server >= 8.0.0, <= 8.0.26 cpe:2.3:a:oracle:mysql_server:*:*:*:*:*:*:*:*

References for CVE-2021-36222

cvelogic Threat Intelligence